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      1 /*
      2 * Copyright (c) 2014 - 2015, The Linux Foundation. All rights reserved.
      3 *
      4 * Redistribution and use in source and binary forms, with or without
      5 * modification, are permitted provided that the following conditions are
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      8 *       notice, this list of conditions and the following disclaimer.
      9 *     * Redistributions in binary form must reproduce the above
     10 *       copyright notice, this list of conditions and the following
     11 *       disclaimer in the documentation and/or other materials provided
     12 *       with the distribution.
     13 *     * Neither the name of The Linux Foundation nor the names of its
     14 *       contributors may be used to endorse or promote products derived
     15 *       from this software without specific prior written permission.
     16 *
     17 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
     18 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
     19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
     20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
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     23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
     24 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
     26 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
     27 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     28 */
     29 
     30 /*! @file core_interface.h
     31   @brief Interface file for core of the display subsystem.
     32 
     33   @details Display core is primarily used for loading and unloading different display device
     34   components viz primary, external and virtual. Display core is a statically linked library which
     35   runs in caller's process context.
     36 */
     37 #ifndef __CORE_INTERFACE_H__
     38 #define __CORE_INTERFACE_H__
     39 
     40 #include <stdint.h>
     41 
     42 #include "display_interface.h"
     43 #include "sdm_types.h"
     44 #include "buffer_allocator.h"
     45 #include "buffer_sync_handler.h"
     46 
     47 /*! @brief Display manager interface version.
     48 
     49   @details Display manager interfaces are version tagged to maintain backward compatibility. This
     50   version is supplied as a default argument during display core initialization.
     51 
     52   Client may use an older version of interfaces and link to a higher version of display manager
     53   library, but vice versa is not allowed.
     54 
     55   A 32-bit client must use 32-bit display core library and a 64-bit client must use 64-bit display
     56   core library.
     57 
     58   Display manager interfaces follow default data structures alignment. Client must not override the
     59   default padding rules while using these interfaces.
     60 
     61   @warning It is assumed that client upgrades or downgrades display core interface all at once
     62   and recompile all binaries which use these interfaces. Mix and match of these interfaces can
     63   lead to unpredictable behaviour.
     64 
     65   @sa CoreInterface::CreateCore
     66 */
     67 #define SDM_REVISION_MAJOR (1)
     68 #define SDM_REVISION_MINOR (0)
     69 
     70 #define SDM_VERSION_TAG ((uint32_t) ((SDM_REVISION_MAJOR << 24) | (SDM_REVISION_MINOR << 16) | \
     71                                     (sizeof(SDMCompatibility) << 8) | sizeof(int *)))
     72 
     73 namespace sdm {
     74 
     75 /*! @brief Forward declaration for debug handler.
     76 */
     77 class DebugHandler;
     78 
     79 /*! @brief This enum represents max bandwidth limit mode.
     80 
     81   @sa DisplayInterface::SetMaxBandwidthMode
     82 */
     83 enum HWBwModes {
     84   kBwDefault,      //!< Default state. No change in device bandwidth limit.
     85   kBwCamera,       //!< Camera is on. Bandwidth limit should be reduced accordingly.
     86   kBwVFlip,        //!< VFlip is required. Reduce bandwidth limit accordingly.
     87   kBwHFlip,        //!< HFlip is required.  Reduce bandwidth limit accordingly.
     88   kBwModeMax,      //!< Limiter for maximum available bandwidth modes.
     89 };
     90 
     91 /*! @brief Display core interface.
     92 
     93   @details This class defines display core interfaces. It contains methods which client shall use
     94   to create/destroy different display devices. This interface is created during display core
     95   CreateCore() and remains valid until DestroyCore().
     96 
     97   @sa CoreInterface::CreateCore
     98   @sa CoreInterface::DestroyCore
     99 */
    100 class CoreInterface {
    101  public:
    102   /*! @brief Method to create and get handle to display core interface.
    103 
    104     @details This method is the entry point into the display core. Client can create and operate on
    105     different display devices only through a valid interface handle obtained using this method. An
    106     object of display core is created and handle to this object is returned via output parameter.
    107     This interface shall be called only once.
    108 
    109     @param[in] debug_handler \link DebugHandler \endlink
    110     @param[in] buffer_allocator \link BufferAllocator \endlink
    111     @param[in] buffer_sync_handler \link BufferSyncHandler \endlink
    112     @param[out] interface \link CoreInterface \endlink
    113     @param[in] version \link SDM_VERSION_TAG \endlink. Client must not override this argument.
    114 
    115     @return \link DisplayError \endlink
    116 
    117     @sa DestroyCore
    118   */
    119   static DisplayError CreateCore(DebugHandler *debug_handler, BufferAllocator *buffer_allocator,
    120                                  BufferSyncHandler *buffer_sync_handler, CoreInterface **interface,
    121                                  uint32_t version = SDM_VERSION_TAG);
    122 
    123   /*! @brief Method to release handle to display core interface.
    124 
    125     @details The object of corresponding display core is destroyed when this method is invoked.
    126     Client must explicitly destroy all created display device objects associated with this handle
    127     before invoking this method.
    128 
    129     @param[in] interface \link CoreInterface \endlink
    130 
    131     @return \link DisplayError \endlink
    132 
    133     @sa CreateCore
    134   */
    135   static DisplayError DestroyCore();
    136 
    137   /*! @brief Method to create a display device for a given type.
    138 
    139     @details Client shall use this method to create each of the connected display type. A handle to
    140     interface associated with this object is returned via output parameter which can be used to
    141     interact further with the display device.
    142 
    143     @param[in] type \link DisplayType \endlink
    144     @param[in] event_handler \link DisplayEventHandler \endlink
    145     @param[out] interface \link DisplayInterface \endlink
    146 
    147     @return \link DisplayError \endlink
    148 
    149     @sa DestroyDisplay
    150   */
    151   virtual DisplayError CreateDisplay(DisplayType type, DisplayEventHandler *event_handler,
    152                                      DisplayInterface **interface) = 0;
    153 
    154   /*! @brief Method to destroy a display device.
    155 
    156     @details Client shall use this method to destroy each of the created display device objects.
    157 
    158     @param[in] interface \link DisplayInterface \endlink
    159 
    160     @return \link DisplayError \endlink
    161 
    162     @sa CreateDisplay
    163   */
    164   virtual DisplayError DestroyDisplay(DisplayInterface *interface) = 0;
    165 
    166   /*! @brief Method to update the bandwidth limit as per given mode.
    167 
    168     @param[in] mode indicate the mode or use case
    169 
    170     @return \link DisplayError \endlink
    171 
    172    */
    173     virtual DisplayError SetMaxBandwidthMode(HWBwModes mode) = 0;
    174 
    175 
    176  protected:
    177   virtual ~CoreInterface() { }
    178 };
    179 
    180 }  // namespace sdm
    181 
    182 #endif  // __CORE_INTERFACE_H__
    183 
    184